Blood Pressure Category Checker

How does this tool sort a reading into a category?

It checks conditions in a fixed order, higher-risk categories first, and stops at the first match. Above 180 systolic or above 120 diastolic gives “Hypertensive Crisis”. Otherwise 140 systolic or 90 diastolic and above gives “Stage 2 Hypertension”, 130 or 80 and above “Stage 1 Hypertension”, and 120 or more systolic with diastolic under 80 “Elevated”. Only then does below 90 systolic or below 60 diastolic give “Low Blood Pressure”, and everything else is “Normal”. These are the figures built into this tool, following the ACC/AHA 2017 categories.

Why is 150/55 not called low blood pressure?

The high-pressure checks run before the low check, so a systolic of 140 or more decides the category even when the diastolic is under 60. The tool prints “Stage 2 Hypertension” for 150/55, with a pulse pressure of 95.0 and a MAP of 86.7. An earlier version of this page labelled that reading low; the order was corrected. Any reading that worries you needs a clinician’s opinion.

Is one reading enough to be labelled?

The tool labels whatever two numbers you type. Blood pressure varies through the day and a category normally rests on several properly taken readings, which the tool cannot assess. It does not ask about arm position, cuff size, recent caffeine or the setting.

What are pulse pressure and MAP?

Pulse pressure is systolic minus diastolic. Mean arterial pressure here is diastolic + (pulse pressure / 3). For 128/76 the tool shows a pulse pressure of 52.0 and a MAP of 93.3, both in mmHg. The tool only calculates these; it gives no ranges for them.

What about the emergency message?

For readings over 180 systolic or 120 diastolic, the tool’s text tells you to seek emergency care. That wording is fixed in the code. If you have chest pain, breathlessness, weakness, confusion or a severe headache with a high reading, do not wait to use a calculator; contact emergency services.

Does it consider age, pregnancy or medication?

No. There are only two inputs. Targets and thresholds differ for children, pregnant people and people with certain conditions, and the tool applies the same adult-style cut points to everyone. The recommendation lines are generic text, not personal advice.

What happens if I leave a field blank?

A zero systolic or diastolic, which is also what a cleared box becomes, shows a prompt to enter both numbers, in mmHg. Negative numbers are treated as zero.

Is this a diagnosis?

No. It is for general information and education, not a diagnosis, and it does not replace clinical judgement. A qualified clinician interprets blood pressure readings in context.